This invention relates to the field of power-line communication (PLC) transmission. This new communication transmission method will operate at transmission rates up to 1.6 gigabits per second capability.
The existing methods for transmitting data communication over the power-line uses various modulation techniques that manipulate a carrier(s) by phase, amplitude and/or frequency. FIG. 1 illustrates a diagram of the conventional modulation techniques used in today's transmission technology.
Referring to FIG. 1, data 10 includes information that may be transmitted over the power line using one of the illustrated transmission techniques. Data 10 is represented by digital signals that are transmitted in strings of binary 1s and 0s. When amplitude modulation technique 20 is used to transmit data 10, the data signal is blended into a carrier by varying the amplitude of the carrier. Specifically, the amplitude is modulated when it corresponds to a binary 0 of the data signal. On-off modulation technique 30 uses a transmitter which is turned off every time the transmitted data signal is represented by a binary 0. When frequency modulation using frequency shift keying (FSK) technique 40 is used, the data signal is blended into a carrier by modulating (shifting) the frequency of the carrier. The frequency shift occurs when a binary 0 in the data signal is encountered. Phase modulation using phase shift keying (PSK) technique 50 shifts the phase (e.g., 180.degree.) when the data signal represented by a binary 0 is transmitted.
Using various modulation techniques, the power-line communication industry has obtained data rates of up to 10 megabits. Some of the above techniques use multiple carrier frequency such as DSS (Digital Spread Spectrum) or OFDM (Orthogonal Frequency Division Multiplexing). The use of spread spectrum and chirping signals used in transmission systems of today also limits the capacity. Using extended duration signaling techniques limits the theoretical transmission rate and rates faster than 40 megabits per second are not practical using such methods.